Many electronic devices include electronic image sensors. Electronic image sensors are often one of two types—CCDs (charge coupled devices) and CMOS-APS (complimentary metal oxide semiconductor—active pixel sensors). Each type of electronic image sensor includes an array of photo-detectors (i.e., pixels) that are arranged in a pattern. Each pixel measures the intensity of light for one of a set of ranges of wavelengths of light in response to being exposed to an image. Each of the sets of ranges may be associated with a color perceived by the human visual system.
Unfortunately, electronic image sensors may include defective pixels. A defective pixel is a pixel that responds inappropriately to exposed light from an image and thereby produces an inaccurate sensor value. A defective pixel may be a stuck high pixel where a pixel has an abnormally high (e.g., full or near full scale) output, a stuck low pixel where a pixel has an abnormally low (e.g., zero or near zero scale) output, or abnormally sensitive pixel where a pixel differs significantly from neighboring pixels that are exposed to the same light conditions.
It would be desirable to be able to accurately detect and correct defective pixels from an electronic image sensor.